1. Field of the Invention
The present invention relates to an apparatus and a process for reducing the moisture content of sawdust. It particularly relates to a dryer apparatus and associated process wherein sawdust passes downwardly in a sinuous fashion to and through multiple, vertically-spaced dryer plates at a temperature and velocity so as to progressively dry the sawdust.
2. Description of the Prior Art
It has been shown that dried sawdust is an excellent, low-cost fuel for use in certain manufacturing operations, for example, in the heating of brick kilns. However, because undried or "green" sawdust has a moisture content on the order of 30-50%, it is not suitable for use as a fuel until the moisture content has been lowered substantially, for example, to about 12% by weight, or less.
Many apparatus and processes have been proposed and investigated over a period of years for reducing the moisture content of various materials. U.S. Pat. Nos. 2,104,526, 2,118,208 and 2,222,673 are representative of patents describing multiple hearth drying and incinerating apparatus for treating sewage sludge. These apparatus include a plurality of vertically-spaced hearths on which the material is "rabbled", with the material passing progressively downwardly to underlying hearths through alternating peripheral and central openings. The material 13 is ultimately burned within the apparatus.
Despite the high level of activity in the development of apparatus and processes for drying moisture laden material, and in many instances thereafter incinerating in the same operation, the need still exists for an effective, commercially feasible apparatus and process for reducing the moisture content of sawdust, rendering it suitable for use as a highly combustible fuel.